Light sensitive cell



Feb. 27, 1934. R. s. LYoN 1,948,766

LIGHT SENSITIVE CELL Iiled oct. 1, 1936 INVENTOR L RAY SH/ TH LYON ATTORNEY Patented Feb. .27, 1934 LIGHT SENSITIVE CELL Ray Smith Lyon, Woodside, N. Y., assignor to United Research Corporation, New York,y N. Y., l a corporation of Delaware Application October 1, 1930. Serial No. 485,788

Claims.

This invention relates to light sensitive cells, and particularly to mounting, supporting, and connecting means therein.

The light sensitive material in a photo-cell must be supported, protected against injury and delel terious influences, and connected to other circuit and more nearly a constant-resistance connection to the photo-sensitive elements in a light sensivtive cell.

Still another object is to reduce the difficulty of obtaining a steacbr non-microphonic connection to the light sensitive electrodes in a photocell device.

A further object is to secure rm electrical connection and adequate protection to a photosensitive member, in a light, compact case member, adapted to be mounted in a simple frame for use in cooperation with a variable beam of light rays.

A still further object is to simplify the manufacture of light sensitive cell mounting devices.

Light sensitive cells have been made in the prior art utilizing a slip of glass forthe insulating member,l a pair of interdigitated electrodes adherent thereto and formed of a tenuous iilm of metal such as platinum for the conductor; and a layer of photo-sensitive material such as selenium over the electrodes. The electrical connection to the electrodes, necessary in order ,that the response of the cell to light variation may be registered on other devices, has previously been made by soldering leads to the electrode lms, but this has been found to be difficult to do and productive of`unsatisfactory results, since it requires veryexact control of the processes for applying the metal to the glass, to avoid failure of the solder to adhere to the metal, and to avoid destruction of the cell by the solder pulling the metal from the glass.

Also, the 'soldered connections were found to be noisy because of various electrical effects in the circuit which may be due to contact potentials-,.thermo-electric effects, microphonic effects. etc. Furthermore the cell elements themselves are delicate and fragile, and must be protected against accidental injury during Ause, and during handling, and it is desirable that provision be made for easy and simple insertion of the cell structure into the circuit and into its operating position.

This invention is a new typeof mounting for a light-sensitive cell which is adapted to provide protection to the fragile elements, adapted to be sealed, adapted to make ycontact with the electrodes in such a way as to avoid previous difficulties from injury to the electrodes, failure of contact, and microphonic and other undesired noises, and one which is simple, easy'to make, inexpensive and convenient to assemble.

The objects` of this invention are thus obtained by the combination of electrodes and pressure springs; and by the combination of the electrodes, sensitive material, pressure contact springs, and annular holder member.

Other objects and structural details of this invention will be apparent from the following description when read in connection with the -accompanying drawing, wherein;

Figure 1 is a top view of an embodiment of the invention, and

Figure 2 is a view in vertical section of the same @embodiment Referring to the gures,.a photo-sensitive member is provided, consisting of a glass slip or plate 1, having an adherent metal film divided by a sinuous trace into interdigitated electrodes 2 and 3. A layer of photo-sensitive material 4 such as selenium is positioned upon the electrodes 2 and 3, and covered by a cup 5, held in place by cement 6, with drying material 'I within the cup. A mounting cylinder 8 of insulating material, is also provided having a central recess, adapted to receive the cup member 5. The glass plate l is positioned adjacent the end of the central recess, and is held there by a perforated metal cap member 9, which is conveniently held in place by an annular edge portion crimped into the annular groove 1l. y

The cap member 9 has a central opening which registers with the interdigitated portions of the electrodes 2 and 3 and the photoLsenstive covering, 4, and permits entrance of light to the sensitive material, while protecting it against Electrical connections are made to the electrodes 2 and 3 by stiff contact springs 12 which are positioned within the openings 14 in the mount 8. 'Ihe openings 14 may conveniently ,be holes drilled through the body of the mount 8 and closed at the back by the terminal plates 15, having binding screws 16, and held in place by attachment screws 17.

The electrodes 2 and 3, on the glass plate 1 are then held rmly against the springs 12 by the cap 9, putting them under a substantial compression. The compression maintains a rm contact pressure between the electrodes and the springs which is found to be of a more stable character than is obtainable by other means such as soldering and shows much less microphonic and other effects from and upon the cell current. In consequence the cell is much more quiet in operation, and the ground noise level lower and less obtrusive.

Also, the crimping together of the cap and body results in a sealed type of construction which prevents displacement of the parts of the cell, and the consequent danger of injury and destruction.

The construction is simple, easily made, and easily assembled. The body member 8, is conveniently made by simple machining operations from such a material as vulcanized fiber or it may be made by a moulding operation using such materials as hard rubber, porcelain, or polymerized resin preparations. The various parts are then conveniently assembled in the obvious manner. When completed, the cell is particularly easy to put into use, since it is readily supported in a simple ring at the desired point, and fastened therein by a set screw, and the lead Wires connected to the binding posts.

By this construction there is thus produced a simple, convenient, quiet, .inexpensive light sensitive-cell device.

While there is here disclosed but a single em bodirnent of this invention it is possible to produce other embodiments thereof without depart. ing from the inventive concept herein disclosed, and it is desired therefore that only such limitations be imposed on the appended claims as are stated therein, or required by the prior art. r

The invention claimed is:

1. A light sensitive cell comprising a pair of substantially plane interdigitated electrodes, a photo-sensitive substance thereon, a protective cup thereover, an annular body member, contact springs and terminal plates attached to said body and adapted to cooperate with said electrodes, and a perforated cap member adapted to hold said electrodes against said springs, and admit light to said sensitive substance.

2. A light sensitive cell comprising a substantially plane sensitive member, a cup shaped cover member cemented thereto, an annular body member concentric therewith and therearound, and a cap member around both thereof.

3. A light sensitive cell comprising a substantially plane sensitive member, a cup shaped cover member cemented thereto, an annular body member concentric therewith and therearound, and a cap member around both thereof, adapted to support said sensitive member at an end of said body -and to admit light to said sensitive member, and contact,'and terminal members cooperating with said sensitive member and supported by said body member.

4. The combination of an annular support member having openings, contact members in said openings, and a photo-sensitive element comprising a transparent insulating support, photo-sensitive material and interdigitated electrodes carried by said transparent support, and a light admitting cap holding said element against said contact members.

5. The combination of a hollow container, and

a glass plate extending across the opening in said container, said plate having interdigitated electrodes and photo-sensitive material thereon, a desiccating chamber enclosing said photo-sensitive material and extending within said container, said container comprising tensioning means and retaining means at opposite sides of said glass plate.

6. The combination of a hollow cylindrical container, springs at opposite sides thereof, and a glass plate having spaced metallic electrodes on the same side of said plate, each of said springs being in contact with one of said metallic electrodes, photo-sensitive material for said electrodes, a desiccating chamber enclosing said photo-sensitive material, said desiccating chamber extending within said container, and an abutment for said container and against which said springs urge said glass plate, said springs serving as electrical terminals for said electrodes respectively.

7. The combination of a cylindrical support and a cover plate therefor comprising a glass disc having spaced metallic electrodes on the inner side thereof, photo-sensitive material for said electrodes, and a cap for holding said disc on said support, said cap having an aperture for admitting light through said disc to said photosensitive material, and electrical terminals for said electrodes.

8. The combination of a light sensitive cell comprising a glass plate, separated metallic electrodes and photo-sensitive material on one side thereof, and a container therefor, a desiccating cup carried by said cell and projecting into said container, spring contacts carried by said container and engaging said electrodes, and a retaining device engaging said container and said plate.

9. A light sensitive cell comprising opposite insulating portions having a light admitting portion therebetween, light sensitive material in register with said light admitting portion, planary interdigitated electrodes for said light sensitive material, said light admitting portion f comprising transparent material in plate form, said light sensitive material and said interdigitated electrodes being mounted on and carried by said transparent material, laterally extending conductors mounted on said insulating portions respectively and connected to said electrodes respectively, and spring terminals adapted to contact with and support said conductors and also adapted to support said insulating portions and said light admitting portion.

10. A light sensitive cell comprising opposite insulating portions having a light admitting portion therebetween, light sensitive material in register with said light admitting portion, planary interdigitated electrodes for said light sensitive material, said light admitting portion comprising transparent material, in plate form, said light sensitive material and said interdigitated electrodes being mounted on and carried by said transparent material, laterally extending conductors mounted on said insulating portions respectively and connected to said electrodes respectively, and terminals adapted to contact with and support said conductors and also adapted to support said insulating portions and said light admitting portion.

RAY S. LYON. 

